uC/OS-II时间(OS_time)块
/*
*********************************************************************************************************
* uC/OS-II
* The Real-Time Kernel
* TIME MANAGEMENT
*
* (c) Copyright 1992-2002, Jean J. Labrosse, Weston, FL
* All Rights Reserved
*
* File : OS_TIME.C
* By : Jean J. Labrosse
*********************************************************************************************************
*/
#ifndef OS_MASTER_FILE
#include "includes.h"
#endif
/*
*********************************************************************************************************
* DELAY TASK 'n' TICKS (n from 0 to 65535)
*
* Description: This function is called to delay execution of the currently running task until the
* specified number of system ticks expires(到期). This, of course, directly equates to delaying
* the current task for some time to expire. No delay will result If the specified delay is
* 0. If the specified delay is greater than 0 then, a context switch will result.
*
* Arguments : ticks is the time delay that the task will be suspended in number of clock 'ticks'.
* Note that by specifying 0, the task will not be delayed.
*
* Returns : none
*********************************************************************************************************
*/
//延时时间
void OSTimeDly (INT16U ticks)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
if (ticks > 0) { /* 0 means no delay! */
OS_ENTER_CRITICAL();
//Delay current task
if ((OSRdyTbl[OSTCBCur->OSTCBY] &= ~OSTCBCur->OSTCBBitX) == 0) { /* Delay current task */
//取消当前的任务状态
OSRdyGrp &= ~OSTCBCur->OSTCBBitY;
}
//延时的节拍数存到任务控制块中
OSTCBCur->OSTCBDly = ticks; /* Load ticks in TCB */
OS_EXIT_CRITICAL();
//触发一次任务调度
OS_Sched(); /* Find next task to run! */
}
}
/*$PAGE*/
/*
*********************************************************************************************************
* DELAY TASK FOR SPECIFIED TIME
*
* Description: This function is called to delay execution of the currently running task until some time
* expires. This call allows you to specify the delay time in HOURS, MINUTES, SECONDS and
* MILLISECONDS instead of ticks.
*
* Arguments : hours specifies the number of hours that the task will be delayed (max. is 255)
* minutes specifies the number of minutes (max. 59)
* seconds specifies the number of seconds (max. 59)
* milli specifies the number of milliseconds (max. 999)
*
* Returns : OS_NO_ERR
* OS_TIME_INVALID_MINUTES
* OS_TIME_INVALID_SECONDS
* OS_TIME_INVALID_MS
* OS_TIME_ZERO_DLY
*
* Note(s) : The resolution on the milliseconds depends on the tick rate. For example, you can't do
* a 10 mS delay if the ticker interrupts every 100 mS. In this case, the delay would be
* set to 0. The actual delay is rounded to the nearest tick.
*********************************************************************************************************
*/
//也是延时函数
#if OS_TIME_DLY_HMSM_EN > 0
INT8U OSTimeDlyHMSM (INT8U hours, INT8U minutes, INT8U seconds, INT16U milli)
{
INT32U ticks;
INT16U loops;
if (hours > 0 || minutes > 0 || seconds > 0 || milli > 0) {
if (minutes > 59) {
return (OS_TIME_INVALID_MINUTES); /* Validate arguments to be within range */
}
if (seconds > 59) {
return (OS_TIME_INVALID_SECONDS);
}
if (milli > 999) {
return (OS_TIME_INVALID_MILLI);
}
/* Compute the total number of clock ticks required.. */
/* .. (rounded to the nearest tick) */
ticks = ((INT32U)hours * 3600L + (INT32U)minutes * 60L + (INT32U)seconds) * OS_TICKS_PER_SEC
+ OS_TICKS_PER_SEC * ((INT32U)milli + 500L / OS_TICKS_PER_SEC) / 1000L;
loops = (INT16U)(ticks / 65536L); /* Compute the integral number of 65536 tick delays */
ticks = ticks % 65536L; /* Obtain the fractional number of ticks */
OSTimeDly((INT16U)ticks);
while (loops > 0) {
OSTimeDly(32768);
OSTimeDly(32768);
loops--;
}
return (OS_NO_ERR);
}
return (OS_TIME_ZERO_DLY);
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* RESUME A DELAYED TASK
*
* Description: This function is used resume a task that has been delayed through a call to either
* OSTimeDly() or OSTimeDlyHMSM(). Note that you MUST NOT call this function to resume a
* task that is waiting for an event with timeout. This situation would make the task look
* like a timeout occurred (unless you desire this effect). Also, you cannot resume a task
* that has called OSTimeDlyHMSM() with a combined time that exceeds 65535 clock ticks. In
* other words, if the clock tick runs at 100 Hz then, you will not be able to resume a
* delayed task that called OSTimeDlyHMSM(0, 10, 55, 350) or higher.
*
* (10 Minutes * 60 + 55 Seconds + 0.35) * 100 ticks/second.
*
* Arguments : prio specifies the priority of the task to resume
*
* Returns : OS_NO_ERR Task has been resumed
* OS_PRIO_INVALID if the priority you specify is higher that the maximum allowed
* (i.e. >= OS_LOWEST_PRIO)
* OS_TIME_NOT_DLY Task is not waiting for time to expire
* OS_TASK_NOT_EXIST The desired task has not been created
*********************************************************************************************************
*/
//This function is used resume a task that has been delayed through a call to either OSTimeDly() or OSTimeDlyHMSM()
#if OS_TIME_DLY_RESUME_EN > 0
INT8U OSTimeDlyResume (INT8U prio)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_TCB *ptcb;
//判断
if (prio >= OS_LOWEST_PRIO) {
return (OS_PRIO_INVALID);
}
OS_ENTER_CRITICAL();
ptcb = (OS_TCB *)OSTCBPrioTbl[prio]; /* Make sure that task exist */
//确定任务存在
if (ptcb != (OS_TCB *)0) {
//See if task is delayed
if (ptcb->OSTCBDly != 0) { /* See if task is delayed */
//Clear the time delay
ptcb->OSTCBDly = 0; /* Clear the time delay */
// See if task is ready to run
if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) == OS_STAT_RDY) { /* See if task is ready to run */
OSRdyGrp |= ptcb->OSTCBBitY; /* Make task ready to run */
OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;
OS_EXIT_CRITICAL();
//task sched
OS_Sched(); /* See if this is new highest priority */
} else {
OS_EXIT_CRITICAL(); /* Task may be suspended */
}
return (OS_NO_ERR);
} else {
OS_EXIT_CRITICAL();
return (OS_TIME_NOT_DLY); /* Indicate that task was not delayed */
}
}
OS_EXIT_CRITICAL();
return (OS_TASK_NOT_EXIST); /* The task does not exist */
}
#endif
/*$PAGE*/
/*
*********************************************************************************************************
* GET CURRENT SYSTEM TIME
*
* Description: This function is used by your application to obtain the current value of the 32-bit
* counter which keeps track of the number of clock ticks.
*
* Arguments : none
*
* Returns : The current value of OSTime
*********************************************************************************************************
*/
#if OS_TIME_GET_SET_EN > 0
INT32U OSTimeGet (void)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
INT32U ticks;
OS_ENTER_CRITICAL();
ticks = OSTime; //The current value of OSTime
OS_EXIT_CRITICAL();
return (ticks);
}
#endif
/*
*********************************************************************************************************
* SET SYSTEM CLOCK
*
* Description: This function sets the 32-bit counter which keeps track of the number of clock ticks.
*
* Arguments : ticks specifies the new value that OSTime needs to take.
*
* Returns : none
*********************************************************************************************************
*/
#if OS_TIME_GET_SET_EN > 0
void OSTimeSet (INT32U ticks)
{
#if OS_CRITICAL_METHOD == 3 /* Allocate storage for CPU status register */
OS_CPU_SR cpu_sr;
#endif
OS_ENTER_CRITICAL();
OSTime = ticks;
OS_EXIT_CRITICAL();
}
#endif
